I do research on security and cryptography, and occasionally release code. Freely available stuff: Linux firewalling: A simple tutorial on setting up firewalling on your personal Linux box, to increase security. http://www.isaac.cs.berkeley.edu/simple-firewall.html Janus: Experimental software for securing untrusted (or untrustworthy) legacy applications from external attack. http://www.cs.berkeley.edu/~daw/janus/ Resources for gathering crypto-quality randomness: http://www.cs.berkeley.edu/~daw/rnd/index.html Old non-security-related work: Some free software for mudding that I've worked on, including the popular tintin++ client. http://www.cs.berkeley.edu/~daw/my-misc.html